Bug #10887

Running a lot slower on a much faster machine

Added by Hiram Mandemaker over 2 years ago. Updated 4 months ago.

Start date:
Due date:
% Done:


Affected Version:
Mac OS X
hardware architecture:


On my new 27 inch iMac (3,3 GHz Intel Core i5, 24 GB 1867 MHz DDR3, AMD Radeon R9 M395 2048 MB, 2TB Fusion Drive, latest system updates installed) darktable runs noticeably slower than on my previous iMac (with a much slower processor, less RAM, and no OpenCL support). All kinds or operations are affected.

I thought maybe things would improve after the cache for the thumbs had been created, but this is not the case.

dt.1.6.9.perf.log Magnifier (14.6 KB) Rafa G., 07/29/2016 02:48 AM

dt.2.0.5.perf.log Magnifier (11.3 KB) Rafa G., 07/29/2016 02:48 AM

dt-2.0.4.log Magnifier (20 KB) Rafa G., 08/04/2016 11:40 PM

dt-2.0.5.log Magnifier (13.6 KB) Rafa G., 08/04/2016 11:40 PM

dt-2.0.4.log Magnifier - Log generated with darktable-cli 2.0.4 (2.64 KB) Rafa G., 08/05/2016 01:06 AM

dt-2.0.5.log Magnifier - Log generated with darktable-cli 2.0.5 (2.64 KB) Rafa G., 08/05/2016 01:06 AM


#1 Updated by Pascal Obry over 2 years ago

What seems to indicate that this is maybe not dt: "All kinds or operations are affected."

Could this be because of the Gtk3 port on MacOS?

Anyway, just guessing as I'm not a MacOS user...

#2 Updated by Hiram Mandemaker over 2 years ago

It's the same OS that I ran on my previous Mac (where darktable was fast enough) and darktable is running like a normal Mac application; the rest of the applications are very fast. So (though I am no coder) I would guess it is a darktable issue.

#3 Updated by Roman Lebedev over 2 years ago

  • Status changed from New to Incomplete
  • % Done changed from 0 to 20


I'll quote:

Without any profiling data - just with the "feeling" value there won't be any help for you.

You need to identify a typical use situation where darktable 2.0 "feels" 
slower than 1.6.9. Then you need to reproducably measure the timings
with '-d perf' (or '-d opencl -d perf') once for 2.0 and then for 1.6.9.

#4 Updated by Tobias Ellinghaus over 2 years ago

You were comparing the same dt version, right?

#5 Updated by Hiram Mandemaker over 2 years ago

Yes, the same version. Also, I'd like to help with what Roman asks me, but I have no idea how. I launch dt from the Mac Finder, never from the terminal. So detailed instructions are welcome...

#6 Updated by Rafa G. almost 2 years ago

I was reading this issue and I did two perf (one for 1.6.9 and another for 2.0.5).

Steps followed once:

  • I removed my .config/darktable path to clean up.
  • I loaded darktable 1.6.9 to generated it again.
  • I imported one photo
Steps followed for each darktable version:
  • I loaded darktable with -d perf option
  • I loaded the photo in darkroom and zoomed(pointing in an eye)
  • Quit darktable
  • Save perf logs

Perf logs/output attached to this comment.

#7 Updated by Rafa G. almost 2 years ago

I installed previous version(2.0.4) and it goes faster than 2.0.5

I don't know if it is related with GTK+3 which it's bugged in 2.0.5(Mac). I mean, dt is working right but GTK seems to be the bottleneck(UI feels laggy).

#8 Updated by Rafa G. almost 2 years ago

I attach 2 perf profiles of dt 2.0.4 and 2.0.5

Steps done for profiling in both versions:
- Open a photo
- Zoom to 200%
- Back to zoom to fit in window
- Go to lighttable
- Quit

#9 Updated by Rafa G. almost 2 years ago

I was speaking with Houz via IRC and he recommended me to execute darktable-cli for the logs files.
Not too much difference between version (2.0.5 a little bit faster than 2.0.4)

I attach the new log files for dt-2.0.4 and dt-2.0.5

#10 Updated by Tobias Ellinghaus almost 2 years ago

Yes, those are so close that it's hardly important. I guess if you ran the same test using the same version 5 times in a row and averaged you would get almost the same times in both versions. So if there really is a speed difference it should be in GUI code or something else not used in darktable-cli. Hard to tell without having the problems myself.

#11 Updated by John Morris over 1 year ago

I recently got a new iMac 27" Retina with a 4G GPU
I am also seeing much more lag than I do on my, theoretically slower, linux machine. The worst problem, as far as usability is concerned, is lag in lighttable between mouse movement and mouse-over highlighting of the thumbnails. The lag can be a little more than 1 second, which makes rating and tagging images quite frustrating. I find the linux version laggy enough (maybe as much as .5 seconds in lighttable) so I really think a general speedup in mouse-over response is needed, in the order of at least 2-3 times faster.

#12 Updated by John Morris over 1 year ago

I should add that there is also lag responding to keyboard navigation in lighttable on my iMac. Again, the lag is also there to a lesser extent on my linux machine.
Another problem is the case where I where I press an arrow key 2 times, thumbnail highlight will move 2 places but pressing 3 times only results in moving 2 places. The third keypress seems to be queued up and not acted upon till another key press. This problem is common to Linux and Mac OSX.

#13 Updated by Rui Carmo 4 months ago

I'd like to add that 2.4.1 still exhibits this issue. Using Darktable on a modern, 2017 iMac is much slower than on an old Linux laptop, and that seems to be almost exclusively due to input and UI lag.

Also available in: Atom PDF